Conventionally, surveillance cameras in each of which a camera and a turntable of the camera are housed within a dome-shaped housing have been on the market. Such a camera is called as a composite camera since both the rotation of the camera in the horizontal direction (panning) and the rotation of the camera in the vertical direction (tilting) can be performed due to the operation of the turntable. The conventional composite camera is able to rotate by 360 degrees to the panning direction endlessly and also able to rotate by 0 to 90 degrees to the tilting direction, that is, from the horizontal direction to the vertical direction.
The group of the inventors of the invention have improved such a composite camera to develop a new composite camera that can rotate by 360 degrees to the panning direction endlessly and rotate by 180 degrees to the tilting direction. This new composite camera can move to a target camera position through the shortest path since the degree of freedom of the moving direction is increased.
As shown in the side sectional view of FIG. 9 and the plan view of FIG. 10, the composite camera includes, within a housing constituted by a cylindrical camera base 107 and a hemispherical camera cover, a surveillance camera 102, a tilting turntable 105 for directly holding the camera 102, a panning turntable 103 capable of rotating endlessly by 360 degrees, a pair of columns 113 provided at the panning turntable 103 so as to elect therefrom, a tilting rotation shaft 106 for pivotally supporting the tilting turntable 105 to the columns 113, and a slip spring 112 acting as a contact for supplying the electric power within the housing and inputting/outputting an electric signal. Although not shown, the composite camera further includes a rotation mechanism for the panning turntable 103 and the tilting turntable 104, a motor serving as the driving source for the rotation, a driving control unit for the motor, an amplifying circuit for amplifying an image signal, and a control unit for controlling the operation of the composite camera, etc. Further, in order to determine the rotation origin point of the panning direction, a magnet 117 is fixed at the origin position of the housing and the panning turntable 103 is provided with an origin hall element 32 for detecting the magnetic field of the magnet 117.
The tilting turntable 105 for holding the camera 102 is able to rotate over 180 degrees around the tilting rotation shaft 106. Thus, the camera 102 can reciprocally turn from a point A (108) to a point C (110) through a lowest point B (109) as shown in FIG. 9.
The panning turntable 103 can rotate over 360 degrees in the horizontal direction as shown by a rotation locus 206 in FIG. 10.
The slip ring 112 realizes the power supply from a fixing portion to a movable portion and the conduction of the electric signal between the fixing portion and the movable portion.
Thus, when this composite camera is attached to the ceiling, then the rotation angle of the tilting turntable 105 is adjusted by the remote control and the panning turntable 103 is rotated to the predetermined angle, the camera 102 can photograph all the direction of the surveillance area.
FIG. 11 is a functional block diagram showing the internal configuration of this composite camera. As the rotation control mechanism for the panning turntable 103 and the tilting turntable 105, the composite camera includes rotating motors 24, 28; encoders 25, 29 for detecting the revolution numbers of the motors 24, 28, respectively; motor drivers 23, 27 for driving the motors 24, 28 based on the detection results, respectively; deceleration mechanisms 26, 30 for decelerating the rotation velocities of the motors 24, 28 and transmitting the decelerated rotation forces to the panning turntable 103 and the tilting turntable 105, respectively; the origin hall element 32 disposed on the panning turntable 103 and responsive to the magnetic field of a magnet 117 disposed at the origin of the punning operation; end point hall elements 33 disposed at the tilting turntable 105 so as to separate by 180 degrees to each other and responsive to the magnetic fields of magnets disposed at the end points of the tilting operation; a hall element detection unit 31 for detecting the origin of the panning operation and the end points of the tilting operation from the detection signals of the hall elements 32, 33; and a motor control unit 22 for controlling the motor drivers 23, 27 based on the detection result of the hall element detection unit 31.
Further, as the control mechanism for a camera lens unit, the composite camera includes stepper motors 36, 40 for adjusting zooming and focusing operations, respectively; motor drivers 35, 39 for outputting driving pulses to the stepper motors 36, 40, respectively; deceleration mechanisms 37, 41 for decelerating the rotation velocities of the stepper motors 36, 40 and transmitting the decelerated rotation forces to the lens mechanism; a limit switch or a photo interrupter 38 for detecting the limit of the zooming adjustment; a photo interrupter 42 for detecting the limit of the focusing adjustment; a lens control unit 34 for controlling the motor drivers 35, 39; and a driver 43 for adjusting an iris.
Further, as a camera unit for outputting an image signal, the composite camera includes a CCD 44 for photographing images, a DSP 45 for coding the image signal, and an image memory 46 for writing and reading image data.
Furthermore, the composite camera includes a camera control unit 21 for controlling the operation of the composite camera based on a control signal inputted from a controller, a memory (E2PROM) 47 for storing data and a timer 49 for counting time.
As shown in FIG. 12, the composite camera is connected to the controller 12 and a monitor 13 through a coaxial cable 16. Alternatively, as shown in FIG. 13, the composite camera is connected to a personal computer 19 through an RS485 cable serving as a communication transmitting means and controlled thereby.
Although, these drawings show the case where the single composite camera 11 is coupled to the controller 12 or the personal computer 19, a plurality of the composite cameras may be coupled to the controller 12 or the personal computer 19 so that these composite cameras are controlled thereby.
In this composite camera, the output pulses of the encoder 25 for detecting the rotation of the motor 24 in the panning direction are transmitted to the motor control unit 22, and the detection timing of the origin of the panning operation detected by the origin hall element 32 is transmitted to the motor control unit 22 through the hall element detection unit 31. Supposing that the encoder 25 outputs p pulses while the panning turntable rotates by one revolution, the motor control unit 22 counts m pulses outputted from the encoder 25 after the origin hall element 32 detects the origin of the panning operation to thereby calculate a current panning angle Pt based on an expression of Pt=m×360/p. The current panning angle Pt thus calculated is held in a storage area (RAM) of the camera control unit 21.
Similarly, the output pulses of the encoder 29 for detecting the rotation of the motor 28 in the tilting direction are transmitted to the motor control unit 22, and also the detection timing of the end point of the tilting operation detected by the end point hall element 33 is transmitted to the motor control unit 22 through the hall element detection unit 31. Supposing that the encoder 29 outputs q pulses while the tilting turntable rotates by a half revolution, the motor control unit 22 counts n pulses outputted from the encoder 29 after the end point hall element 33 detects the end point of the tilting operation to thereby calculate a current tilting angle Tt based on an expression of Tt=90−(n×180/q). That is, the tilting angle is calculated in a manner that the beneath direction is 0 degree. The range of the tilting angle is in a range of +90 degrees to −90 degrees. The current tilting angle Tt thus calculated is held in the RAM.
The view angle of an image photographed by the lens unit is determined by the rotation amount of the stepper motor 36 for defining the zooming amount, and the rotation amount is determined by the number of pulses outputted to the stepper motor 36. Similarly, the focal distance of the lens unit is determined by the number of the pulses outputted to the stepper motor 40. The lens control unit 34 counts up the pulses outputted for rotating the stepper motors 36, 40 in the positive direction and counts down the pulses outputted for rotating the stepper motors in the negative direction to thereby accumulate the numbers of pulses outputted from the motor drivers 35, 39, respectively. These accumulated numbers of the pulses are held in the RAM as data representing the current view angle Zt and the current focal distance Ft.
In this manner, Pt, Tt, Zt and Ft are held in the RAM as the data representing the current status amounts of the composite camera.
In the case of controlling the operation of the composite camera, the controller 12 of FIG. 12 or the personal computer 19 of FIG. 13 transmits a command to the composite camera. The camera control unit 21 of the composite camera 11 interprets the received command to control the operations of the respective units thereof.
For example, in the case of setting a preset position, an operator operates the controller 12 to remotely control the direction of the camera to thereby direct the camera position of the composite camera 11 toward a target preset position.
When the operator inclines the joystick 14 of the controller 12 in order to change the direction of the camera, in response to this operation, the controller 12 transmits to the composite camera 11 data Vpan representing the X-axis component and data Vtilt representing the Y-axis component of the slanted joystick 14 as shown in FIG. 14 together with a command for instructing the velocity control of the camera. The camera control unit 21 of the composite camera 11 interprets the received command and sends the data Vpan and the data Vtilt to the motor control unit 22, whereby the motor control unit 22 controls the motor driver 23 so as to perform the panning rotation at the velocity of Vpan and also controls the motor driver 27 so as to perform the tilting rotation at the velocity of Vtilt.
When the operator moves the joystick back to a neutral position, in the similar manner as described above, data Vpan=0 and data Vtilt=0 are sent to the composite camera together with a command, whereby both the rotation in the tilting direction and the rotation in the panning direction is stopped.
As described above, when the camera changes its direction, the data Pt, Tt, Zt and Ft representing the current status amount of the camera are updated and held in the RAM.
When the operator confirms on the monitor screen that the composite camera 11 is directed to the target direction, the operator remotely operates the zoom amount as the need arises and thereafter inputs the instruction of the presetting and the ID of the preset position by means of the controller 12 or the personal computer 19. The presetting instruction command including the ID is sent to the composite camera 11. The camera control unit 21 interprets this command and stores the data Pt, Tt, Zt and Ft representing the current status amounts of the composite camera in the memory 47 together with the ID.
Such operations are repeatedly performed to thereby set a plurality of preset positions in the memory 47 as shown in FIG. 15.
Then, in the case where the operator operates the controller 12 or the personal computer 19 to designate the ID (for example, ID=2) of the preset position to thereby instruct the photographing at the preset position, the camera control unit 21 of the composite camera 11 interprets the received command, then reads the data P2, T2, Z2 and F2 representing the status amounts of the preset position of ID=2 from the memory 47 and compares these status amounts with the data representing the current status amounts Pt, Tt, Zt and Ft stored in the RAM to obtain the shortest path from the current camera position to the preset position of ID=2. Then, the camera control unit instructs the motor control unit 22 so as to perform the panning rotation by a required panning rotation angle and also perform the tilting rotation by a required tilting rotation angle. Further, the camera control unit instructs the lens control unit 34 to output pulses of (Z2–Zt) to the zooming stepper motor 36 and to output pulses of (F2–Ft) to the focusing stepper motor 36.
The motor driver 23 rotates the motor 24 by the panning rotation angle instructed through the motor control unit 22 and stops the rotation of the motor 24 when the detection is made based on the output from the encoder 25 that the motor 24 has rotated by the instructed rotation angle. Similarly, the motor driver 27 rotates the motor 28 by the tilting rotation angle instructed through the motor control unit 22 and stops the rotation of the motor 28 when the detection is made based on the output from the encoder 29 that the motor 28 has rotated by the instructed rotation angle. As a result, the camera is directed to the preset position of ID=2 and starts the photographing in the lens state at the time of the presetting. Incidentally, the iris is adjusted by activating the driver 43 in accordance with the brightness of a subject to be photographed at that time.
The CCD 44 photographs an image to which the camera is directed. An image signal from the CCD is coded by the DSP 45 and stored in the image memory 46. Then, the image signal thus coded is read from the image memory 46 and outputted to the monitor 13.
It is possible to have the composite camera storing a plurality of preset positions perform the surveillance operation for automatically monitoring the respective preset positions sequentially, that is, the auto tracing operation.
Further, it is possible to have the composite camera perform the automatic panning operation for continuously photographing while performing the panning rotation automatically at a constant velocity.
When the hall element detection unit 31 detects the origin of the panning operation or the endpoint of the tilting operation during the panning rotation or the tilting rotation, the camera control unit 21 refers to the current status amount Pt or Tt of the composite camera held in the memory to thereby reset (reset of the coordinate system) the Pt or Tt to a correct value when the value of the Pt corresponding to the origin is not 0 or when the value of the Tt upon detecting the end point of the tilting operation is not 90 degrees.
Furthermore, this composite camera can photograph color images at the daytime and also photograph black-and-white images at the night. In this case, color images can be photographed by attaching an IR (infrared ray) filter for suppressing the infrared rays to the camera, whilst black-and-white images can be photographed by removing the IR filter in order to raise the sensitivity. The attaching and removing operation of the IR filter can be performed mechanically by using a motor.
However, according to such an apparatus which can perform such complicated operations and cope with various usages of users, if the apparatus becomes failure, it is difficult to determine a cause of the failure. Thus, in most cases, the apparatus thus failed can not be repaired immediately even when a service man go to the site.
Accordingly, the invention is intended to solve the aforesaid conventional problems and an object of the invention is to provide a surveillance camera and a method of recording operation history there of which can record the operation history of the composite camera and remain information important for repairing the camera.